How can I change IntProperty default value?
You can't do that to an actual instance:

import bpy
bpy.types.Object.prop = bpy.props.IntProperty()

bpy.context.active_object.prop
# this evaluates what the value is and returns &lt;class 'int'&gt; - not subscriptable




To adjust the min max etc. you need to re-declare it:

bpy.types.Object.prop = bpy.props.IntProperty(min=100, max=300)
# note: re-declaring will change it for all the objects


Changing the default value will not change the actual value of that static property - you will need to assign it a new value in that case. But newly created objects will have this new default.

You can make it work like this:


create callback function for your hT property
have this function re-declare your fW property with new parameters based on hT value